Stitch separating machines



Jan. 29, 1963 A. P. cHARRoN ETAL 3,075,211

STITCH SEPARATING MACHINES 4 Sheets-Sheet 1 Filed Sept. l2, 1961 Inventor/S Jan. 29, 1963 A. P. CHARRON En.. 3,075,211

STITCH SEPARATING MACHINES Filed sept. 12, 1961 4 Sheets-Sheet 2 Jan. 29, 1963 Filed Sept. 12, 1961 A. P. CHARRON ETAI- STITCH SEPARATING MACHINES 4 Sheets-Sheet 3 Jan. 29, 1963 A. P. cHARRoN ETAL 3,075,211 STITCH SEPARATING MACHINES Filed Sept. l2, 1961 4 Sheets-Sheet 4 United States Patent Oiiice 3,075,211 Patented Jan. 29, 1963 3,075,211 STITCH SEPARATING MACHINES Antonio P. Charron and William D. McKeon, Beverly,

Mass., assignors to United Shoe Machinery Corporation, Flemington, NJ., a corporation of New Jersey Filed Sept. 12, 1%1, Ser. No. 137,654 8 Claims. (Cl. 12-32.1)

This .invention relates generally to stitch separating machines adapted to operate upon the edge of shoe soles to indent the interval between the stitches land more par- Iticularly to improvements in linear braking devices or locks useful in such machines for resisting the force of indentation.

The present invention is useful as an improvement in a machine of the type disclosed in United States Letters Patent No. 1,357,511, issued November 2, 1920, upon an application til-ed in the name of Frederick H. Perry. In the prior machine the work support consists of a conical table rotatably mounted upon the upper end of a vertical slide, the table receiving the shoe bottom .as the edge of the shoe is presented vto an indenting tool. In the conventional machine the s-lide is locked aga-inst the force of the indenting tool by means of a ratchet cooperating with a set of staggered pawls.

Although the ratchet is of a relatively line pitch further divided by the staggering of the pawls, it frequently occurs that a min-nte change in the thickness of the shoe edge produces an appreciable change in the locking position of the work support slide and a consequent sudden and readily noticeable variation in the depth of indention.

In addition, the -conventional lock for the work support slide also requires that a rack be formed in the slide and engaged by a gear sector. This combination of parts is expensive to construct and to assemble and the pawls and ratchet, in addition to their inherent inaccuracy, are subject to rapid wear, occasional breakage, and frequent and expensive replacement.

Because the o leration of a .stitch separating machine continues as a completed shoe is removed and the next shoe is presented to the machine, the operator is subjected to fatigue causing forces. In the above-identified Perry machine which opera-tes 800 to 1000 cycles per minute the locking pawls are released from the ratchet only during a small fraction of each operating cycle; consequently the lowering of the table which is accomplished by a treadle depressed by the operator does not occur during a single operating cycle but is linterrupted several times and this interrupted motion is coupled through the treadle to the body of the operator.

It is accordingly an object of the present invention to provide a stitch separating machine in which the depth of indentation is much more uniform than has heretofore been possible.

It is another object to provide a lock for the work support slide of a stitch separating machine which arrests the slide under conditions of uniform indenting tool pressure for successive stitches, despite variationsr in the thickness of the work so that the depth of indentation is regular and independent of work thickness.

it is a further object to provide a lock for the work support lslide of a stitch separator which operates with uniformity and yet is economical to construct.

A still further object is to provide a lock of the type already indicated which is not only inexpensive to construct but also durable in use so as to result in still greater over-all economy.

Still further objects are to provide a lock which is readily accessible for installation and replacement and yet which may be installed in a machine of conventional de- 2 sign without extensive modification of the actuatingmechanisms..

It is `an additional object to provide a package which may be employed for modifying machines .in the 'eld without the need for elaborate equipment.

The foregoing objects are achieved in a `machine according to the present invention inV which lthe work sup'- port slide -is arrested by a bar engaged by four interconnected rollers of a conventional roller chain. According to another feature of the invention, the rst or uppermost roller is normally free to rotate on a fixed axis and a locking force is applied to the fourth roll of the chain which is located on the same side of the ybar -as the rst roll. The second and third intermediate rolls are positioned on the opposite side of the bar from the first and fourth, and the thickness of the bar is calculated with respect to the spacing between the rolls of the chain to provide a locking angle of approximately 7, .the locking angle being that defined between an axial plane of the first roll perpendicular to the thicknessV of the bar and the line of centers interconnecting` the first and the second rolls.

Operator fatigue is reduced according. to another feature of the present invention by providing an electrical solenoid which when energized by closing a foot switch applies aconstant table lowering force to the slide. Since the solenoid is coupled to the foot switch by flexible wires only, the stepswise .lowering of 'the table, which has already been mentioned and which is found objectionable, isnotcoupled to the body of the operator so that not only is the operator free of vibration but also the minimal p-ressure required for closing the foot switch is muchl less than needed. in prior machines for lowering the work support ing table.

According to still another feature,V the chain lock, the locking ba-r, the solenoid and associated devices are mounted o-n a supporting plate which may be readily incorporated for modifying existing machines `in the field without requiring the use of complex equipment or procedures.

The foregoing objects and features and numerous advantages such as serviceability and economy of construction will be realized from the following description of an illustrative embodiment taken in connection with the drawings, in which:

FIG. 1 is a general View in left side elevation of a stitch separating machine incorporating a lock according to the present invention;

FIG. 2 is a view in front elevation and on a larger scale showing work manipulating, supporting, and indenting devices in -the machine of FIG. 1;

FIG'. 3kv is a fragmentary view illustrating on a larger scale the lock depicted -in FIG. 1, together with related machine elements;

FIG. 4 is a View in front elevation of that portion of the machine depicted in FIG. 3;

FIG. 5 is. a detail view in cross section taken along the line V.V of FIG. 3 illustrating the construction of thek lock; and

FIGS. 6 and7 are views in left side elevation and partly in cross section showing the lock in unlocked and locked condition, respectively.

The present machine, except as will hereinafter be pointed out, is similar to the machine of the above-identified Perry patent as may be seen from FIGS. 1 and 2,. As in the Perryv machine the present one includes a conical work supporting table 10 upon which the bottom `of the shoe is received' as' the margin of the shoe is presented to an indenting tool 12. During a part of each op'- erartingv cycle of the machine, one cycle consisting of the indentation of a single stitch, the' manipulation of the shoe is assisted by a pair of presser feet 14 moved into and out of engagement with the margin of the shoe by means of a cam mounted on a main shaft 16. The indenting tool 12 also receives its movements for stitch findng and for indenting from cams mounted on the shaft i6 which is rotatable in a housing 17 and driven one revolution for each machine cycle by a belt 18, which, for this purpose, passes over a pulley 19 on the rearward end of the shaft.

The operation of the present machine after the margin Vof the shoe has been interposed between the table 10 and the tool 12 is also similar to that of the Perry machine. While the presser feet 14 clamp the margin of the shoe on 'the supporting table 1li the indenting tool 12 descends into engagement with the upper surface of the shoe margin. An oscillating movement is imparted to the tool 12 so that the tool finds the stitch interval between the forwardly and rearwardly extending legs of the top thread bight lying on the surface of the welt. After the oscillating part of the indenting tool movement is completed it is pressed further toward the table to form an indentation in line with the stitch hole and at about the same time the presser feet 14 are released from clamping engagement with the sole edge. During the indenting operation the work supporting table 10 is locked against the pressure ofthe indenting tool and the table remains locked as the indenting tool feeds the shoe approximately one stitch length from right to left as seen in FIG. 2. At the end of the work feeding movement the presser feet 14 descend into engagement with the welt, the indenting tool 12 is raised and backfed, and the vertical support of the table 10 is released so that it may be repositioned according to the thickness of the particular portion of the work piece then being operated upon to provide uniform depth of indentation as determined from the upper surface of the work.

As in the patented machine, the work support table 10 is rotatably supported about an adjustably fixed inclined axis at the upper end of a work support slide 20 arranged to move in a vertical guideway in a bracket 21 xedly mounted on the front of the housing 17 carried by a ped- 'estal 22. The bottom of the guideway is closed by a Wall in which is threaded an adjusting bushing 24. Passing through the bushing 24 and threaded into the slide 20 is a rod 26 surrounded by a compression spring 28, shown in FIG. 3, which urges the slide 20 upwardly. The upward force acting upon the slide 20 is regulated by adjusting the position of the bushing 24 against which the lower end ofthe spring 28 acts and a stop collar 30 is adjustably clamped upon the rod 26 for limiting the upward movement of the slide.

The lower end of the rod 26 is threaded to receive an enlarged head 32 formed with a flat-bottomed, roundended slot into which is received the upper end f a vertical locking bar 34 connected to the head 32 by means of a screw 36 passing loosely through the bar and threaded linto a tapped hole in the bottom wall of the slot. The -bar 34 is interposed between rolls of a chain lock denoted generally by the reference numeral 38 which grips and releases the bar once during each operating cycle of the machine.

The lock 38, as seen in FIGS. to 7 inclusive, comprises a first roll 40 rotatable upon a pin 42 xedly supported in the forward end of a bracket 44. In addition to the roll 40, the lock 38 also includes a pair of intermediate rolls 46 and 48 mounted one above the other on the side of the bar opposite the roll 40. Interconnecting the rolls 40 and 46 is a pair of links 50 and a pair of vertical links 52 connects the intermediate rolls 46 and 48. Finally, the lock also includes a terminal roll 54 connected to the roll 48 by means of a pair of links 56.

In order to cause the bar 34 to be gripped by the rolls of the lock 38, a downwardly directed force is applied to the roll S4 and when it is desired to release the bar 34 the roll 54 is raised by appropriate mechanism provided in the machine to be hereinafter described. The roll 54 is rotatable on a pin 58 passing loosely through the upwardly extending arms of a U-shaped yoke urged downwardly by a tension spring 62. The locking force supplied by the spring 62 is adjustable by means of a check nut 64 threaded onto an adjusting screw 66 which passes loosely through a bracket 67.

For raising the roll 54 against the force of the spring 62 to release the lock there is provided an L-shaped release bar 68 which engages the links 56 so that the roll 54 remains free to rotate. At its upper end the bar 68 is adjustably connected to a vertical link rod 70 by a pair of opposed check nuts 72, a hub being provided on the bar 68 and closely fitted to the link rod to avoid rele.- tive displacement of the two elements. As may be seen from FIGS. 5 and 6 the lower end of the bar 68 passes through a slot in the bracket 44 which restrains the bar against lateral movement. At its upper end, the rod 70 is pivotally connected to a lever 74 corresponding to the lever 180 of the above-identied Perry patent. The lever 74 is oscillated once during each operating cycle of the machine to release the lock 38 thereby allowing the slide 20 to be urged upwardly under the influence of the spring 28 or to be moved downwardly thereagainst and to reengage the lock to resist the pressure of the indenting tool during the actual indentation and as the shoe is being fed a distance equal to a stitch length.

A seriou-s problem encountered in stitch separating machines stems from the fact that while operating at speeds Vas high as 800 to 1000 cycles a minute the work table supporting slide must be locked and released once during each operating cycle and the locking and releasing action takes place during a brief portion of each cycle. In the Perry machine, for example, although it is not specifically stated in the specification, the unlocking action of the table takes place during 30 of cam shaft rotation. At an operating speed of 900 cycles per minute this results in the slide changing from locked to unlocked condition in a period of approximately 51/2 milliseconds. Little diflicultyis experienced in the Perry machine when the machine is new but after appreciable wear both the locking and unlocking action become sluggish and unreliable and the parts of the lock must be replaced.

In the present lock, the holding action under a given locking force exerted by the spring 62, which is adjustable, and the effective release time are determined by a locking angle A as shown in FIG. 7, the angle A being defined by the line of centers of the rolls 40, 46, in bar-locking condition, identified by the reference numeral 80 and a line 82 representing a plane perpendicular to the parallel surfaces of the bar 34. Greatest holding action under a given locking force is obtained when the locking angle A is at a minimum on the order of l or 2 degrees but under these circumstances greater motion is required to cause the rolls to grip and to release the bar 34. On the other hand if the locking angle A is substantially increased the amount of motion of the rolls 46, 48 and 54 required for locking and unlocking is reduced and the speed of operation is accordingly increased but there is less holding action under a given locking force exerted by the spring 62. It has been found that a locking angle of 7 degrees is an acceptable compromise for adequate locking action to resist the force of the iudeuting tool and to provide the necessary speed of gripping and release of the bar 34 to meet the operating requirements of the machine. It is convenient to employ a chain No. 60 of the American Chain Manufacturers Standard in which the pitch is .750",the roll diameter .469" and the roll width at 500". With this standard chain a har having a thickness of slightly more than .275" provides the preferable 7 degree locking angle A. It will be understood that with a diterent chain the bar thickness will necessitate adjustment but that the same conditions will obtain in that a reduction in bar thickness will increase the angle A and vice versa.

A deficiency of the Perry machine which has been overcome according to a feature of the present invention relates to the treadle actuated downward movement of the work support during the presentation of a new shoe to be operated upon. In the Perry machine the work table supporting slide is connected to a treadle which, when depressed by the operator, causes the table ,to be lowered in an interrupted motion occurring during that portion of several operating cycles that the lock is released. The arrangement of the Perry machine is such that the operator is subjected to fatigue-causing vibration occurring each time a shoe is presented to the machine. In order to reduce fatigue in the present machine the table is lowered by means of a solenoid 3'4jhaving an armature .86 connected by means of an intermediate rod 88 to the lower end of the lock bar 34. The solenoid 84 is in series with a normally open foot switch 90, FIG. 1, connected across the power line. The only connection between the locking bar 34 and the foot switch 90 is by means of wires 92, 94, which effectively isolates the operator from the vibration incident to lowering the table. When the solenoid S4 is energized by closing the foot switch 90 the armature 86 is drawn downwardly to cause lowering of the slide during the portion of several machine cycles that the lock 38 is released.

In order to facilitate the modification of machines already in existence a supporting structure has been provided which may readily be incorporated in such machines. The supporting structure includes a plate 96 clamped between the pedestal 22 and the housing 17 and a vertical strap 98 fixedly depending from the forward margin of the plate. The strap 9S is connected to the pedestal 22 by means of a pair of screws 100 passing loosely through the strap and into threaded engagement with tapped holes in the pedestal. In addition, a set screw 102 threaded in the strap and locked by a check nut 104 bears against the forward surface of the pedestal 22 to tighten the strap 98 against the screws 100. The bracket 44 and the solenoid 814 are fixedly supported upon the plate 98 as is also bracket 67 to which the spring 62 is connected.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent of the United States is:

1. A stitch separating machine including a work support, a vertical slide upon which the work support is rotatably mounted, an indenting tool, means for imparting to the tool stitch hole finding, indenting and work advancing movements, in combination with a lock for arresting the downward movement of the slide against the pressure of the indenting tool comprising a bar depending from the lower end of the slide, and a bar locking means cornprising a plurality of rolls located on opposite sides of the bar, links interconnecting said rolls, means for moving one of said rolls lengthwise of the bar with respect to a roll on the opposite side of the bar to lock the bar therebetween, and means for moving said one of said rolls in the opposite direction to release the bar once during each operating cycle of the machine.

2. A stitch separating machine including a work support, a vertical slide upon which the work support is rotatably mounted, an indenting tool, means for imparting to the tool stitch hole finding, indenting, and work advancing movements, in combination with a -lock for arresting downward movement of the slide against the pressure of the indenting tool comprising a bar depending from the lower end of the slide, and a bar locking means comprising a roller chain consisting of four rolls and three intermediate pairs of interconnecting links, the first roll of which is mounted for rotation about a fixed axis, means for applying a locking force to the last roll, and means for pressing the last roll toward the first for releasing the bar regularly once during each operating cycle of the machine.

3. A stitch separating machine including a work support, a vertical slide upon which the work support is rotatably mounted, an indenting tool, means for imparting to the tool stitch hole finding, indenting, and work advancing movements, in combination with a lock for arresting downward movement of the slide against the pressure .of the indenting tool comprising a bar depending from the lower end of ,the slide, ,and a bar locking means comprising a roller chain comprising four rolls and three intermediate `pairs of interconnecting links, the first roll of which is mounted for rotation about a fixed axis, the second and third rolls .being on the side of the bar opposite the first roll, means for -applying a locking force vto the last roll, and means for pressing the last roll ltoward the first for releasing the bar regularly Once during each operating cycle ,of the machine.

4. A stitch separating machine including Aa work support, a vertical slide Iupon which the work support is rotatably mounted, an indenting tool, means for imparting to the tool stitch hole finding, indenting, and work advancing movements, in combination with a lock for arresting downward movement of the slide against the pressure of the indenting tool comprising a bar depending from the lower end of the slide, and a bar locking means comprising a roller chain consisting of four rolls and three intermediate pairs of interconnecting links, the first roll of which is mounted for rotation about a fixed axis, the second roll being connected to the first by a pair of links lying across the bar and the line of centers of the first and second rolls defining a locking angle of between five and nine degrees with a plane normal to the thickness of the bar, means for applying a locking force to the last roll, and means for pressing the last roll toward the first for releasing the bar regularly once during each operating cycle of the machine.

5. A stitch separating machine including a work support, a vertical slide upon which the work support is rotatably mounted, an indenting tool, means for imparting to the tool stitch hole finding, indenting, and work advancing movements, in combination with a lock for arresting downward movement of the slide against the pressure of the indenting tool comprising a bar depending from the lower end of the slide, and a bar locking means comprising a roller chain consisting of four rolls and three intermediate pairs of interconnecting links, the rst roll of which is mounted for rotation about a fixed axis, and the last roll of which is located on the same side of the bar as the first roll, means for applying a locking force to the last roll, and means for pressing the last roll toward the first for releasing the bar regularly once during each operating cycle of the machine.

6. In a stitch separating machine including a pedestal, a work support, an indenting tool for operating upon the margin of a shoe sole on the work support, and a slide upon which the work support is mounted, the cornbination of a locking bar connected to the slide, a chain lock means engaging the bar and comprising a first roll rotatable on -a fixed axis on one side of the bar, a pair of intermediate rolls on the opposite side of the bar and a terminal roll on the same side of the bar as the first roll, means for applying a bar locking force to the last roll, means for overcoming the bar locking force to release the bar once during each operating cycle of the machine, means for pulling upon the bar to cause movement of the table away from the indenting tool and a supporting structure attachable to the pedestal mounting the elements of the combination.

7. In a stitch separating machine including a pedesal, a housing supported on the pedestal, a work support, an indenting tool for operating upon the margin of a shoe sole on the work support, and a slide upon which the work support is mounted, the combination of a locking bar connected to the slide, a chain lock means engaging the bar and comprising a first roll rotatable on a fixed axis on one side of the bar, a pair of intermediate rolls on the opposite side of the bar and a terminal roll on the same side of the bar as the first roll, means for applying a bar locking force to the last roll, means for overcoming the bar locking force to release the bar once during each operating cycle of the machine, means for pulling upon the bar to cause movement of the table away from the indenting tool and a supporting structure comprising a plate'clamped between the pedestal and the housing and a strap connected to the pedestal for mountingV the elements of the combination.

8. In a stitch separating machine including a pedestal, a work support, an indenting tool for operating upon the margin of a shoe sole on the work support, and a slide upon which -the work support is mounted, the comhination of a locking bar connected to the slide, a chain vlock means. engaging the bar and comprising a rst roll rotatable on a Xed axis on one side of the bar, a.V pair of intermediate rolls on the opposite side of the bar and 'a last roll on the same side of the bar as the rst roll, means for 'applying a Abar locking force to the terminal References Cited in the tile of this patent UNITED STATES PATENTS Perry Nov. 2, 1920 Sjoberg Apr. 1, 1958 

1. A STITCH SEPARATING MACHINE INCLUDING A WORK SUPPORT, A VERTICAL SLIDE UPON WHICH THE WORK SUPPORT IS ROTATABLY MOUNTED, AN INDENTING TOOL, MEANS FOR IMPARTING TO THE TOOL STITCH HOLE FINDING, INDENTING AND WORK ADVANCING MOVEMENTS, IN COMBINATION WITH A LOCK FOR ARRESTING THE DOWNWARD MOVEMENT OF THE SLIDE AGAINST THE PRESSURE OF THE INDENTING TOOL COMPRISING A BAR DEPENDING FROM THE LOWER END OF THE SLIDE, AND A BAR LOCKING MEANS COMPRISING A PLURALITY OF ROLLS LOCATED ON OPPOSITE SIDES OF THE BAR, LINKS INTERCONNECTING SAID ROLLS, MEANS FOR MOVING ONE OF SAID ROLLS LENGTHWISE OF THE BAR WITH RESPECT TO A ROLL ON THE OPPOSITE SIDE OF THE BAR TO LOCK THE BAR THEREBETWEEN, AND MEANS FOR MOVING SAID ONE OF SAID ROLLS IN THE OPPOSITE DIRECTION TO RELEASE THE BAR ONCE DURING EACH OPERATING CYCLE OF THE MACHINE. 